Yes. But he scored some ugly goals using his but, knees or chest. I don't think that counts as good technique but more like little miracles and good luck/timing. Messi or Xavi have good technique. Don't get me wrong, I love Pippo, myself being an AC Milan fan.
Because of his poor technique, his 18 finishing won't appear as that on the pitch. He will need a lot of space to trap that ball. If you look at how the German researcher gives extreme attributes to players in Germany, 19 in technique, dribbling etc are often paired with 9 finishing and composure. This "balances" the players just as well as the English way of giving 12-14 in everything.
So yes you are right - all the technical attributes are linked to physical and mental ones (and other technical). I know that was not your point, but you are right anyways.
It is unlikely, but is possible. Jan Huntelaar is an example of someone who is very good at shooting, but doesn't possess the greatest technique. Diego Forlan is another. Okay, I wouldn't say these players should have technique of 8, but nevertheless it's not unquestionable for a player to be exceptional at shooting at goal, but otherwise possess rather poor technique.
EDIT - I meant to say Cavani, not Forlan. Forlan has nice technique.
To me the player has the accuracy of finishing (which the Finishing attribute is) but lacks the technical ability to score great goals.
The player will get the ball on target more often than not because of the high Finishing attribute but because he lacks Technique he'll not be able to bend it around the 'keeper as well, aim a curled shot to a top corner, pull off over head kicks as much or score great volleys.
He'll get the ball on target a lot but might not score a huge amount of goals - yet - because of the lack of technique he has to place the shot rather than just hit it.
Technique for me means being able to do the same thing in a lot of different ways. Like passing the ball. You can hit a weighted throughball or a dinked pass into the same space, to the same player, but its definitely not the same pass. If you can hit a bouncing ball as well as you hit a ball fully under control that is good technique, as well. Curling a cross in, curling a shot in, again are the result of good technique. Like how creativity determines how many passing options a player has, technique determines how many ways there are to get the ball to the intended recipient. Thats just how I envision it, personally.